NH2-Terminal Targeting Motifs Direct Dual Specificity A-Kinase–anchoring Protein 1 (D-AKAP1) to Either Mitochondria or Endoplasmic Reticulumстатья из журнала
Аннотация: Subcellular localization directed by specific targeting motifs is an emerging theme for regulating signal transduction pathways. For cAMP-dependent protein kinase (PKA), this is achieved primarily by its association with A-kinase–anchoring proteins (AKAPs). Dual specificity AKAP1, (D-AKAP1) binds to both type I and type II regulatory subunits and has two NH2-terminal (N0 and N1) and two COOH-terminal (C1 and C2) splice variants (Huang et al., 1997. J. Biol. Chem. 272:8057). Here we report that the splice variants of D-AKAP1 are expressed in a tissue-specific manner with the NH2-terminal motifs serving as switches to localize D-AKAP1 at different sites. Northern blots showed that the N1 splice is expressed primarily in liver, while the C1 splice is predominant in testis. The C2 splice shows a general expression pattern. Microinjecting expression constructs of D-AKAP1(N0) epitope-tagged at either the NH2 or the COOH terminus showed their localization to the mitochondria based on immunocytochemistry. Deletion of N0(1-30) abolished mitochondrial targeting while N0(1-30)-GFP localized to mitochondria. Residues 1–30 of N0 are therefore necessary and sufficient for mitochondria targeting. Addition of the 33 residues of N1 targets D-AKAP1 to the ER and residues 1–63 fused to GFP are necessary and sufficient for ER targeting. Residues 14–33 of N1 are especially important for targeting to ER; however, residues 1–33 alone fused to GFP gave a diffuse distribution. N1(14-33) thus serves two functions: (a) it suppresses the mitochondrial-targeting motif located within residues 1–30 of N0 and (b) it exposes an ER-targeting motif that is at least partially contained within the N0(1-30) motif. This represents the first example of a differentially targeted AKAP and adds an additional level of complexity to the PKA signaling network.
Год издания: 1999
Авторы: Lily Huang, Lin Wang, Yuliang Ma, Kyle Durick, Guy Perkins, Thomas J. Deerinck, Mark H. Ellisman, Susan S. Taylor
Издательство: Rockefeller University Press
Источник: The Journal of Cell Biology
Ключевые слова: Signaling Pathways in Disease, Ubiquitin and proteasome pathways, RNA and protein synthesis mechanisms
Другие ссылки: The Journal of Cell Biology (PDF)
The Journal of Cell Biology (HTML)
Europe PMC (PubMed Central) (PDF)
Europe PMC (PubMed Central) (HTML)
PubMed Central (HTML)
PubMed (HTML)
The Journal of Cell Biology (HTML)
Europe PMC (PubMed Central) (PDF)
Europe PMC (PubMed Central) (HTML)
PubMed Central (HTML)
PubMed (HTML)
Открытый доступ: bronze
Том: 145
Выпуск: 5
Страницы: 951–959